Underdog is your on-device AI OS.
It runs Woof, a small but mighty AI model entirely on your device. Woof 1.1 has 4B parameters, takes up <2.5GB, and handles browser use, tool calls, and long tasks.
Woof runs fast and power efficiently thanks to Greyhound, our self-improving inference engine built for Apple Silicon. We’re making it faster every day.
The current Underdog Woof 4B is on par with GPT 5.0 on things we care about. We’re working towards matching current frontier model performance on consumer devices by the end of the year. Fully locally!
You own your data & AI, as you should.